Heriot-Watt researchers in flame shell reef discovery

A huge colony of an elusive and brightly coloured shellfish species, possibly the largest of its kind in the world, has been mapped by Heriot-Watt researchers in coastal waters in the west of Scotland.

Flame shell reefs

The study, commissioned by Marine Scotland, surveyed an area of Loch Alsh, a sea inlet between Skye and the Scottish mainland, and discovered a 75 hectare reef of flame shells, a small, scallop-like species with numerous neon orange tentacles which emerge between the creatures' two shells. Flame shells group together on the sea bed and their nests create a living reef that support hundreds of other species.

Flame shells (Limaria hians) build €˜nests' by binding gravel and shells together with thin wiry threads. Flame shells, which are around 4 cm in length, group together in such numbers that the sea bed is covered by a felt-like organic reef of nest material several centimetres thick. Internationally, flame shells are considered scarce and beds are found in only eight sites in Scottish waters.

The Loch Alsh flame shell reef is much larger than expected, with the overall population of flame shells in this area is likely to exceed 100 million, and is the largest known flame shell reef anywhere in the UK and possibly the world.

Marine Protected Areas

The survey, carried out by Heriot-Watt University on behalf of Marine Scotland, was part of work to identify new Marine Protected Areas (MPAs). Marine Scotland has coordinated a programme of eight surveys during 2012, including Loch Alsh, covering more than 640 square miles of sea.

Environment Secretary Richard Lochhead said, "The seas around Scotland are a hotbed of biodiversity and the clean and cold waters support many fascinating and beautiful species. With Scottish waters covering an area around five times bigger than our landmass, it's a huge challenge to try and understand more about our diverse and precious sea life.

"The flame shell must be considered among the most remarkable species in our waters, with a dazzling array of orange tentacles. Many would place such an exotic species in far-flung tropical reefs, not realising they dwell under the waves just off the coast of Skye.

"This important discovery may be the largest grouping of flame shells anywhere in the world. And not only are flame shells beautiful to look at, these enigmatic shellfish form a reef that offers a safe and productive environment for many other species."

Dan Harries, of Heriot-Watt University's School of Life Sciences, said, "Too often, when we go out to check earlier records of a particular species or habitat we find them damaged, struggling or even gone. We are delighted that in this instance we found not just occasional patches but a huge and thriving community extending right the way along the entrance narrows of Loch Alsh. This is a wonderful discovery for all concerned."

Photo copyright Graham Saunders